Field of the Invention
The present invention relates to a gas supply manifold for use in a constitutional element of a gas powered water heating apparatus and a gas combustion device provided with the gas supply manifold.
Description of the Related Art
Generally, a gas combustion device provided for a gas powered water heating apparatus has a plurality of burner heads (combustion pipes) for burning fuel gas arranged in a burner case and fuel gas is supplied from a gas supply manifold into the burner heads.
The gas supply manifold is disclosed in, for example, Patent Literatures 1 and 2. The gas supply manifold disclosed in these Patent Literatures has a main body provided with a plurality of gas injection nozzles and has a cover member overlapped on the main body via a sealing packing. The cover member constitutes a gas supply flow path between the cover member and the main body and is fastened to the main body with a screw. The cover member and the main body are manufactured by pressing a metal plate.
In such a configuration, the number of members and the production cost of the gas supply manifold are reduced. In addition, the gas supply manifold is made thin and the weight is reduced.
However, there is still room for improvement in the related art as mentioned below.
It is desired that the production cost of the gas supply manifold be further reduced and the weight reduction be further promoted comparing with the related art. For this purpose, the thickness (sheet thickness) of the cover member can be reduced. However, when the thickness is merely reduced, the cover member easily twists and causes deformation such as warp. Such deformation causes leakage of fuel gas out of the gas supply flow path formed between the cover member and the main body. Therefore, there is need for appropriately preventing such problems.
The number of screwed portions of the cover member to the main body can be increased for suppressing warp and deformation of the cover member. In such a case, the screwing procedure becomes complicated and the production cost increases. Further, even when the number of the screwed portions is increased, it is difficult to adequately suppress warp and deformation of the cover member.